Gender differences in the mental health impact of the COVID-19 lockdown:Longitudinal evidence from the Netherlands

Recent contributions highlighted gender differences in the mental health consequences of COVID-19 lockdowns. However, their cross-sectional designs cannot differentiate between pre-existing gender differences and differences induced by lockdowns. Estimating fixed-effects models using longitudinal data from the Lifelines biobank and cohort study with repeated mental health measurements throughout the lockdown, we overcome this caveat. Significant gender differences in mental health during the lockdown were found, where women experienced more depression symptoms and disorders and men experienced more anxiety symptoms and disorders stemming from the lockdown. Policymakers need to keep in mind that the COVID-19 lockdowns have different effects on mental health for men and women

No Country for Old Men: Aging Dictators and Economic Growth

This paper develops a model of the relationship between the age of a dictator and economic growth. In the model a dictator must spread the resources of the economy over his reign but faces mortality and political risk. The model shows that if the time horizon of the dictator decreases, either due to an increase of mortality risk or political risk, the economic growth rate decreases. The model predictions are supported by empirical evidence based on a three-way fixed effects model including country, year and dictator fixed effects for a sample of dictators from 116 countries. These results are robust to sample selection, the tenure of dictators, the definition of dictatorship, and a broad set of economic growth determinants

No country for old men:Aging dictators and economic growth

Why do some autocracies have higher economic growth rates than others? An emerging literature is highlighting that in addition to economic and institutional variables, personal characteristics of political leaders affect economic growth rates. Within this tradition, we develop a political-economic growth model of the relationship between the age of a dictator and economic growth. The model predicts that if a dictator's mortality risk increases, the economic growth rate in his country decreases. The model predictions are supported by empirical evidence based on a large sample of more than 400 dictators from 76 countries. A 1-year increase in dictator age, decreases economic growth by 0.12 percentage points. Using random leadership transitions due to natural deaths or terminal illnesses we establish that this effect is not driven by endogenous sample selection. As expected, the effect is absent in democratic political regimes

Inequality in an Equal Society

A society in which everybody of a given age has the same income will exhibit substantial income and wealth inequality. We use this idea to empirically quantify inter‐cohort inequality – the share of observed inequality attributable to life‐cycle profiles of income and wealth – using data on male earnings and household wealth. We document that recent increases in income and wealth inequality in the USA and other developed countries are larger than observed rates would suggest due to favourable demographics. That is, while demographic change played a substantial role in the dynamics of income and wealth inequality until 1990, the stark increase in inequality in the USA and elsewhere ever since is despite not because of demographic change. Moreover, we show that there is important variation across countries in the level and trends in the extent of inequality that is due to lifecycle effects, and that taking this into account gives a more nuanced view of cross‐country comparisons

Multiple-Peptidase Mutants of Lactococcus lactis Are Severely Impaired in Their Ability To Grow in Milk

To examine the contribution of peptidases to the growth of Lactococcus lactis in milk, 16 single- and multiple-deletion mutants were constructed. In successive rounds of chromosomal gene replacement mutagenesis, up to all five of the following peptidase genes were inactivated (fivefold mutant): pepX, pepO, pepT, pepC, and pepN. Multiple mutations led to slower growth rates in milk, the general trend being that growth rates decreased when more peptidases were inactivated. The fivefold mutant grew more than 10 times more slowly in milk than the wild-type strain. In one of the fourfold mutants and in the fivefold mutant, the intracellular pools of amino acids were lower than those of the wild type, whereas peptides had accumulated inside the cell. No significant differences in the activities of the cell envelope-associated proteinase and of the oligopeptide transport system were observed. Also, the expression of the peptidases still present in the various mutants was not detectably affected. Thus, the lower growth rates can directly be attributed to the inability of the mutants to degrade casein-derived peptides. These results supply the first direct evidence for the functioning of lactococcal peptidases in the degradation of milk proteins. Furthermore, the study provides critical information about the relative importance of the peptidases for growth in milk, the order of events in the proteolytic pathway, and the regulation of its individual components.

Retention of gait stability improvements over 1.5 years in older adults:effects of perturbation exposure and triceps surae neuromuscular exercise

The plantarflexors play a crucial role in recovery from sudden disturbances to gait. The objective of this study was to investigate whether medium (months)- or long(years)-term exercise-induced enhancement of triceps surae (TS) neuromuscular capacities affects older adults' ability to retain improvements in reactive gait stability during perturbed walking acquired from perturbation training sessions. Thirty-four adult women (65 +/- 7 yr) were recruited to a perturbation training group (n = 13) or a group that additionally completed 14 wk of TS neuromuscular exercise (n = 21), 12 of whom continued with the exercise for 1.5 yr. The margin of stability (MoS) was analyzed at touchdown of the perturbed step and the first recovery step following eight separate unexpected trip perturbations during treadmill walking. TS muscle-tendon unit mechanical properties and motor skill performance were assessed with ultrasonography and dynamometry. Two perturbation training sessions (baseline and after 14 wk) caused an improvement in the reactive gait stability to the perturbations (increased MoS) in both groups. The perturbation training group retained the reactive gait stability improvements acquired over 14 wk and over 1.5 yr. with a minor decay over time. Despite the improvements in TS capacities in the additional exercise group. no benefits for the reactive gait stability following perturbations were identified. Therefore, older adults' neuromotor system shows rapid plasticity to repeated unexpected perturbations and an ability to retain these adaptations in reactive gait stability over a long time period, but an additional exercise-related enhancement of TS capacities seems not to further improve these effects. NEW & NOTEWORTHY Older adults' neuromotor system shows rapid plasticity to repeated exposure to unexpected perturbations to gait and an ability to retain the majority of these adaptations in reactive recovery responses over a prolonged time period of 1.5 yr. However, an additional exercise-related enhancement of TS neuromuscular capacities is not necessarily transferred to the recovery behavior during unexpected perturbations to gait in older adults